So here is the first edition of my front end, called IV/Play. It's basically my favorite things about MameUI decoupled into a standalone that (the plan is) will be futureproof against core changes since it relies on the Mame.inis directly. I started designing it back in 2006 but the latest memory increase and brittleness of MameUI pushed me over the edge so I commissioned its coding.

We have many of the UI navigation short-cuts from MameUI. It can have your favorites displaying at the same time as the game list at the top, so no toggling folder views. You get random background selection, icon zoom to see the 16x16 icons increase in size to 32px. Snapshots and flyers are supported in normal, vertical stretch, and a super large view. Opacity on the art is selectable. (SuperLarge and opacity 50% can look nice, see the pic on the homepage.) The ctrl-f filter is there to filter out name, manufacturer, driver.c, and year. Alt-Enter Properties on the games, adding / removing favorites directly w/ key combos.